Toms928

Hi everyone. I'm a newbie. Just bought a 88 928 s4 AT with only 46k miles on it. It is in very good condition. I'll post pictures later for everyone to see. I'm excited about getting my 928. I love the way it drives and handles.

My question is what type of oil to use. There are so many post and I don't have the time to go through all of them, so I'm asking for your advice. From what I see they have changed the specs or additives in oil during the last few years. I do want to put in synth. oil, and from what I read, everyone recommends a 5w-40 or 10W-40. I went to 4 different stores and in Mobil 1 or any other brand, the only 40 oil they had was a 10w-40 high mileage. They had some 0w-40 or 0w-30, 5w-30 and 10w-30. They did have some Mobil 1 and other brands in 10w-40 for diesel engines. So I figured that wouldn't be good to put in my car because of different additives. Are the 5w or 10w 30's okay or do I need to order some 5w-40 or 10w-40 from someone who sells it. I live in South MS. Please advise which should I be using. Thanks in advance to all who respond. Look forward to your answers.

Tom

Landseer

I like Mobile 1 15W-50 and would use it in your climate.
There has been much written here about new oils not having certain additives necessary for these cars.
This one is an exception.
Am in virginia. Using it in 84,5 and 6 928's. Holds oil pressure better than the specified shell rotella in hot weather.

Dark Blue

Do a search on oil and you will find many recommendations. For some, oil choice seems to take on almost a religious significance. Doug Hillary provided some excellent empirical evidence using oil analysis on his S4 in Australia.

That being said, I've been using Mobil 1 15W-50 in my 89 S4 for over fifteen years and have been very happy with its performance.

Steve
'89 S4 Auto

Tom928

Hi Tom - Welcome to the list!

+1 on the Mobile 1 15w-50. I use it in both my 928's.

Cheers,

Leon Speed

0w,5w and 10W -40 are all ok, never use xw-30.

Edit; in hot climate 0W or 5W might be thin.

Toms928

Thanks for all the replies. Looks like Mobil 1 15w-50 is the way to go. Thanks for the comments about the xw-30. That is the one that most of the auto parts places carry. I wasn't sure if it would make a difference. Some of the other post I read mentioned using xw-40 and since I couldn't find any, that was why I asked. I do remember seeing some 15w-50 at one of the stores.

RKD in OKC

If you ask, most of the stores will either start stocking heavier grades OR already have it in the back somewhere.

NoVector

The added bonus - WalMart sells Mobil 1, 15x50 in the 5L jugs

GlenL

Amsoil

Fogey1

Wanna think about oil? Got a few days?

Here are links to Doug Hillary's oil dissertations and a bunch of other threads. More than you ever wanted to know about oil, unless you're a petroleum engineer:

Oil Condition Report No 12
https://rennlist.com/forums/928-foru...t-no-12-a.html

Oil Condition Report No 11
https://rennlist.com/forums/928-foru...t-no-11-a.html

Oil Condition No 10
https://rennlist.com/forums/928-foru...t-no-10-a.html

Used oil analysis - thrust bearing wear
https://rennlist.com/forums/928-foru...ring-wear.html

Oil condition report No 9 - '89 S4
https://rennlist.com/forums/928-foru...o-9-89-s4.html

Engine oil used when racing
https://rennlist.com/forums/928-foru...en-racing.html

Oil Condition Report No 8 - Delvac 1 5w-40
https://rennlist.com/forums/928-foru...1-5w-40-a.html

Oil Condition Report No 7
https://rennlist.com/forums/928-foru...rt-no-7-a.html

Oil condition report No 6
https://rennlist.com/forums/928-foru...rt-no-6-a.html

PS Fluid
https://rennlist.com/forums/928-foru...-ps-fluid.html

Racing engine oils - "short list"
https://rennlist.com/forums/928-foru...hort-list.html

Oil Condition Report No 5
https://rennlist.com/forums/928-foru...rt-no-5-a.html

Oil Condition Report No 4
https://rennlist.com/forums/928-foru...rt-no-4-a.html

Oil Condition Report No 3
https://rennlist.com/forums/928-foru...rt-no-3-a.html

Oil Condition Report No 2
https://rennlist.com/forums/928-foru...rt-no-2-a.html

Oil condition report
https://rennlist.com/forums/928-foru...on-report.html

ENGINE OIL SAMPLING - 928S4 - M2842-81K
https://rennlist.com/forums/928-foru...m2842-81k.html


Will oil make a difference, yes it does
https://rennlist.com/forums/928-foru...s-it-does.html

Budget Oils.
https://rennlist.com/forums/928-foru...et-oils-2.html

here is a posted pdf by andrew with alot of cool facts to help make decisions
https://rennlist.com/forums/6374650-post26.html

https://rennlist.com/forums/928-foru...pidemic-2.html

jcorenman

Tom,

One of the most important considerations is the "ZDDP" level, that is a zinc/phosphorus additive that provides hi-pressure lubrication to help protect the cam tappets. SM-rated oils in the "normal" 0-30 range are limited by EPA to zinc/phosphorus levels less than 800, which many (most?) folks here consider inadequate.

Mobil-1 15w-50 has high ZDDP levels, as does Amsoil ARO 20w50, as does Torco TR-1 20w-50 (Greg Brown's favorite), Brad Penn 20w50 and others. I would use any of those.

The good news is that the 928 motor-- in warmer climes-- is spec'ed for heavier weight oil such as 15w-50 and 20w-50 which makes finding higher ZDDP levels simpler (EPA limits don't apply). The various 15w40 oils tend to have lower ZDDP levels, check the spec's carefully. For very cold climates you might need to go less than 15W as the first number, but not MS I think.

Some good info in this thread, and what I found about the ratings:
https://rennlist.com/forums/928-foru...ml#post5724722

Also do some more searching, good keywords are ZDDP, zinc, phosphorus, amsoil+mobil (a search-shortcut for "amsoil" and "mobil" in the same post ), "Doug Hillary", etc.

Cheers,

Stromius

Doh..beat me to it. Truely a great deal.

Ducman82

castol 20w50 here

Toms928

Thanks for all the replies. Lots of good info. My wife is already fussing about how long I've been on the computer. My concern was after reading previous post was the zinc, etc changes in some of the oil and that is why I'm asking because I knew all of you were more up to date on it than I was.

Normally it doesn't get what I call "real cold" except this past week. We have seen temps in the mid to lower teens. Normally might get down to the lower 20's two or three days a winter. So with that in mind do you still think the 15w-50 would still be okay? Thanks

Landseer

Working for me every day.